Re: [RFC PATCH v5 15/29] KVM: selftests: TDX: Add TDX MSR read/write tests

+void verify_guest_msr_writes(void) +{

• struct kvm_vcpu *vcpu;
• struct kvm_vm *vm;
• uint64_t data;
• int ret;
• vm = td_create();
• td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
• /*

• * Set explicit MSR filter map to control access to the MSR registers
  

• * used in the test.
  

• */
  

• printf("\t ... Setting test MSR filter\n");
• ret = kvm_check_cap(KVM_CAP_X86_USER_SPACE_MSR);
• TEST_ASSERT(ret, "KVM_CAP_X86_USER_SPACE_MSR is unavailable");
• vm_enable_cap(vm, KVM_CAP_X86_USER_SPACE_MSR, KVM_MSR_EXIT_REASON_FILTER);
• ret = kvm_check_cap(KVM_CAP_X86_MSR_FILTER);
• TEST_ASSERT(ret, "KVM_CAP_X86_MSR_FILTER is unavailable");
• ret = ioctl(vm->fd, KVM_X86_SET_MSR_FILTER, &tdx_msr_test_filter);
• TEST_ASSERT(ret == 0,

•     "KVM_X86_SET_MSR_FILTER failed, ret: %i errno: %i (%s)",
  

•     ret, errno, strerror(errno));
  

• vcpu = td_vcpu_add(vm, 0, guest_msr_write);
• td_finalize(vm);
• printf("Verifying guest msr writes:\n");
• printf("\t ... Running guest\n");
• /* Only the write to MSR_IA32_MISC_ENABLE should trigger an exit */
• td_vcpu_run(vcpu);
• TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
• data = tdx_test_read_64bit_report_from_guest(vcpu);
• TEST_ASSERT_EQ(data, TDG_VP_VMCALL_INVALID_OPERAND);
• td_vcpu_run(vcpu);
• TDX_TEST_ASSERT_SUCCESS(vcpu);
• printf("\t ... Verifying MSR values writen by guest\n");
• TEST_ASSERT_EQ(vcpu_get_msr(vcpu, MSR_X2APIC_APIC_ICR), 4);
• TEST_ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_MISC_ENABLE), 0x1800);

It's not staightforward to assert MSR_IA32_MISC_ENABLE is 0x1800. Rather than assume MSR_IA32_MISC_ENABLE is reset to (MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL | MSR_IA32_MISC_ENABLE_BTS_UNAVAIL) which is 0x1800, why not call vcpu_get_msr() before guest write and compare the saved value here?

• TEST_ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_POWER_CTL), 6);
• kvm_vm_free(vm);
• printf("\t ... PASSED\n");

+}

int main(int argc, char **argv) { setbuf(stdout, NULL); @@ -531,6 +738,8 @@ int main(int argc, char **argv) run_in_new_process(&verify_get_td_vmcall_info); run_in_new_process(&verify_guest_writes); run_in_new_process(&verify_guest_reads);

• run_in_new_process(&verify_guest_msr_writes);
• run_in_new_process(&verify_guest_msr_reads);

return 0; } -- 2.43.0.472.g3155946c3a-goog